Prevent circular fragment fetching between apps

fetch_fragment() auto-returns "" when called inside a fragment request
(detected via X-Fragment-Request header). This prevents deadlocks when
e.g. blog fetches cart-mini from cart, and cart's context processor
fetches nav-tree from blog.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

browser/templates/_types/root/header/_oob.html

@@ -23,9 +23,10 @@
 {% endif %}
   <div class="flex flex-col items-center flex-1">
     <div class="flex w-full justify-center md:justify-start">
-      {# Cart mini #}
-      {% from '_types/cart/_mini.html' import mini with context %}
-      {{mini()}}
+      {# Cart mini — rendered via fragment #}
+      {% if cart_mini_html %}
+        {{ cart_mini_html | safe }}
+      {% endif %}
 
       {# Site title #}
       <div class="font-bold text-5xl flex-1">

browser/templates/macros/cart_icon.html

@@ -0,0 +1,31 @@
+{# Cart icon/badge — shows logo when empty, cart icon with count when items present #}
+
+{% macro cart_icon(count=0, oob=False) %}
+<div id="cart-mini" {% if oob %}hx-swap-oob="{{oob}}"{% endif %}>
+  {% if count == 0 %}
+  <div class="h-12 w-12 rounded-full overflow-hidden border border-stone-300 flex-shrink-0">
+    <a
+      href="{{ blog_url('/') }}"
+      class="h-full w-full font-bold text-5xl flex-shrink-0 flex flex-row items-center gap-1"
+    >
+      <img
+        src="{{ site().logo }}"
+        class="h-full w-full rounded-full object-cover border border-stone-300 flex-shrink-0"
+      >
+    </a>
+  </div>
+  {% else %}
+    <a
+      href="{{ cart_url('/') }}"
+      class="relative inline-flex items-center justify-center text-stone-700 hover:text-emerald-700"
+    >
+      <i class="fa fa-shopping-cart text-5xl" aria-hidden="true"></i>
+      <span
+        class="absolute top-1/2 left-1/2 -translate-x-1/2 -translate-y-1/2 inline-flex items-center justify-center rounded-full bg-emerald-600 text-white text-sm w-5 h-5"
+      >
+        {{ count }}
+      </span>
+    </a>
+  {% endif %}
+</div>
+{% endmacro %}

browser/templates/macros/layout.html

@@ -26,7 +26,17 @@
   <summary class="bg-white/90">
     <div class="flex flex-row items-start">
       <div>
-        {% include '_types/blog/mobile/_filter/_hamburger.html' %}
+        <div class="md:hidden mx-2 bg-stone-200 rounded">
+          <span class="flex items-center justify-center text-stone-600 text-lg h-12 w-12 transition-transform group-open/filter:hidden self-start">
+            <i class="fa-solid fa-filter"></i>
+          </span>
+          <span>
+            <svg aria-hidden="true" viewBox="0 0 24 24"
+                  class="w-12 h-12 rotate-180 transition-transform group-open/filter:block hidden self-start">
+              <path d="M6 9l6 6 6-6" fill="currentColor"/>
+            </svg>
+          </span>
+        </div>
       </div>
       <div
         id="{{id}}"
@@ -37,8 +47,8 @@
 
         </div>
       </div>
-      {% import '_types/browse/mobile/_filter/search.html' as s %}
-      {{ s.search(current_local_href, search, search_count, hx_select) }}
+      {% from 'macros/search.html' import search_mobile %}
+      {{ search_mobile(current_local_href, search, search_count, hx_select) }}
     </div>
   </summary>
 {%- endmacro %}

browser/templates/macros/search.html

@@ -0,0 +1,83 @@
+{# Shared search input macros for filter UIs #}
+
+{% macro search_mobile(current_local_href, search, search_count, hx_select) -%}
+    <div
+      id="search-mobile-wrapper"
+      class="flex flex-row gap-2 items-center flex-1 min-w-0 pr-2"
+    >
+      <input
+        id="search-mobile"
+        type="text"
+        name="search"
+        aria-label="search"
+        class="text-base md:text-sm col-span-5 rounded-md px-3 py-2 mb-2 w-full min-w-0 max-w-full border-2 border-stone-200 placeholder-shown:border-stone-200 [&:not(:placeholder-shown)]:border-yellow-200"
+        hx-preserve
+        value="{{ search|default('', true) }}"
+        placeholder="search"
+        hx-trigger="input changed delay:300ms"
+        hx-target="#main-panel"
+
+        hx-select="{{hx_select}}, #search-mobile-wrapper, #search-desktop-wrapper"
+        hx-get="{{ (current_local_href ~ {'search': None}|qs)|host }}"
+        hx-swap="outerHTML"
+        hx-push-url="true"
+        hx-headers='{"X-Origin":"search-mobile",  "X-Search":"true"}'
+        hx-sync="this:replace"
+        autocomplete="off"
+      >
+
+        <div
+          id="search-count-mobile"
+          aria-label="search count"
+          {% if not search_count %}
+            class="text-xl text-red-500"
+          {% endif %}
+        >
+          {% if search %}
+            {{search_count}}
+          {% endif %}
+        </div>
+    </div>
+{%- endmacro %}
+
+{% macro search_desktop(current_local_href, search, search_count, hx_select) -%}
+  <div
+    id="search-desktop-wrapper"
+    class="flex flex-row gap-2 items-center"
+  >
+    <input
+      id="search-desktop"
+      type="text"
+      name="search"
+      aria-label="search"
+      class="w-full mx-1 my-3 px-3 py-2 text-md rounded-xl border-2 shadow-sm border-white placeholder-shown:border-white [&:not(:placeholder-shown)]:border-yellow-200"
+      hx-preserve
+      value="{{ search|default('', true) }}"
+      placeholder="search"
+      hx-trigger="input changed delay:300ms"
+      hx-target="#main-panel"
+
+      hx-select="{{hx_select}}, #search-mobile-wrapper, #search-desktop-wrapper"
+      hx-get="{{ (current_local_href ~ {'search': None}|qs)|host}}"
+      hx-swap="outerHTML"
+      hx-push-url="true"
+      hx-headers='{"X-Origin":"search-desktop", "X-Search":"true"}'
+      hx-sync="this:replace"
+
+      autocomplete="off"
+    >
+
+    <div
+        id="search-count-desktop"
+        aria-label="search count"
+        {% if not search_count %}
+          class="text-xl text-red-500"
+        {% endif %}
+      >
+        {% if search %}
+          {{search_count}}
+        {% endif %}
+        {{zap_filter}}
+      </div>
+  </div>
+{%- endmacro %}

db/session.py

@@ -15,7 +15,8 @@ _engine = create_async_engine(
     future=True,
     echo=False,
     pool_pre_ping=True,
-    pool_size=0,  # 0 = unlimited (NullPool equivalent for asyncpg)
+    pool_size=5,
+    max_overflow=10,
 )
 
 _Session = async_sessionmaker(
@@ -63,11 +64,17 @@ def register_db(app: Quart):
             # If an exception occurred OR we didn't commit (still in txn), roll back.
             if hasattr(g, "s"):
                 if exc is not None or g.s.in_transaction():
-                    if hasattr(g, "tx"):
-                        await g.tx.rollback()
+                    if hasattr(g, "tx") and g.tx.is_active:
+                        try:
+                            await g.tx.rollback()
+                        except Exception:
+                            pass
         finally:
             if hasattr(g, "s"):
-                await g.s.close()
+                try:
+                    await g.s.close()
+                except Exception:
+                    pass
 
     @app.errorhandler(Exception)
     async def mark_error(e):

infrastructure/fragments.py

@@ -5,8 +5,8 @@ Each coop app exposes HTML fragments at ``/internal/fragments/{type}``.
 This module provides helpers to fetch and cache those fragments so that
 consuming apps can compose cross-app UI without shared templates.
 
-All functions return ``""`` on error (graceful degradation — a missing
-fragment simply means a section is absent from the page).
+Failures raise ``FragmentError`` by default so broken fragments are
+immediately visible rather than silently missing from the page.
 """
 
 from __future__ import annotations
@@ -31,6 +31,10 @@ _DEFAULT_TIMEOUT = 2.0
 FRAGMENT_HEADER = "X-Fragment-Request"
 
 
+class FragmentError(Exception):
+    """Raised when a fragment fetch fails."""
+
+
 def _get_client() -> httpx.AsyncClient:
     global _client
     if _client is None or _client.is_closed:
@@ -55,17 +59,35 @@ def _internal_url(app_name: str) -> str:
 # Public API
 # ------------------------------------------------------------------
 
+def _is_fragment_request() -> bool:
+    """True when the current request is itself a fragment fetch."""
+    try:
+        from quart import request as _req
+        return bool(_req.headers.get(FRAGMENT_HEADER))
+    except Exception:
+        return False
+
+
 async def fetch_fragment(
     app_name: str,
     fragment_type: str,
     *,
     params: dict | None = None,
     timeout: float = _DEFAULT_TIMEOUT,
+    required: bool = True,
 ) -> str:
     """Fetch an HTML fragment from another app.
 
-    Returns the raw HTML string, or ``""`` on any error.
+    Returns the raw HTML string.  When *required* is True (default),
+    raises ``FragmentError`` on network errors or non-200 responses.
+    When *required* is False, returns ``""`` on failure.
+
+    Automatically returns ``""`` when called inside a fragment request
+    to prevent circular dependencies between apps.
     """
+    if _is_fragment_request():
+        return ""
+
     base = _internal_url(app_name)
     url = f"{base}/internal/fragments/{fragment_type}"
     try:
@@ -77,10 +99,20 @@ async def fetch_fragment(
         )
         if resp.status_code == 200:
             return resp.text
-        log.debug("Fragment %s/%s returned %s", app_name, fragment_type, resp.status_code)
+        msg = f"Fragment {app_name}/{fragment_type} returned {resp.status_code}"
+        if required:
+            log.error(msg)
+            raise FragmentError(msg)
+        log.warning(msg)
         return ""
-    except Exception:
-        log.debug("Fragment %s/%s failed", app_name, fragment_type, exc_info=True)
+    except FragmentError:
+        raise
+    except Exception as exc:
+        msg = f"Fragment {app_name}/{fragment_type} failed: {exc}"
+        if required:
+            log.error(msg)
+            raise FragmentError(msg) from exc
+        log.warning(msg)
         return ""
 
 
@@ -88,15 +120,16 @@ async def fetch_fragments(
     requests: Sequence[tuple[str, str, dict | None]],
     *,
     timeout: float = _DEFAULT_TIMEOUT,
+    required: bool = True,
 ) -> list[str]:
     """Fetch multiple fragments concurrently.
 
     *requests* is a sequence of ``(app_name, fragment_type, params)`` tuples.
-    Returns a list of HTML strings in the same order.  Failed fetches
-    produce ``""``.
+    Returns a list of HTML strings in the same order.  When *required*
+    is True, any single failure raises ``FragmentError``.
     """
     return list(await asyncio.gather(*(
-        fetch_fragment(app, ftype, params=params, timeout=timeout)
+        fetch_fragment(app, ftype, params=params, timeout=timeout, required=required)
         for app, ftype, params in requests
     )))
 
@@ -108,11 +141,11 @@ async def fetch_fragment_cached(
     params: dict | None = None,
     ttl: int = 30,
     timeout: float = _DEFAULT_TIMEOUT,
+    required: bool = True,
 ) -> str:
     """Fetch a fragment with a Redis cache layer.
 
     Cache key: ``frag:{app}:{type}:{sorted_params}``.
-    Returns ``""`` on error (cache miss + fetch failure).
     """
     # Build a stable cache key
     suffix = ""
@@ -133,7 +166,7 @@ async def fetch_fragment_cached(
 
     # Cache miss — fetch from provider
     html = await fetch_fragment(
-        app_name, fragment_type, params=params, timeout=timeout,
+        app_name, fragment_type, params=params, timeout=timeout, required=required,
     )
 
     # Store in cache (even empty string — avoids hammering a down service)